"Factory Girls: From Village to City in a Changing China" by Leslie T. Chang offers readers a chance to witness humankind's largest migration — from the small towns in rural China to the factories that lure workers to the country's big cities.

In the decade since she left her village at 17 to work in China's coastal factory cities, Chunming Wu has stirred paint and mixed plastic. She toiled and plotted her ascent from factory worker bee to office clerk to direct-sales queen — from earning less than $1 per day to $5,000 per month — only to watch it all disappear nearly overnight in the industrial Wild West that is China's Guangdong province.

Wu's story is among myriad (mis)adventures packed into the pages of "Factory Girls: From Village to City in a Changing China," Wall Street Journal reporter Leslie T. Chang's narrative that follows the lives of small-town girls (and boys) whose city-bound journeys since the 1980s represent the largest migration in human history: 130 million strong.

Their destinations? Industrial powerhouse cities like Dongguan, bursting with factories that churn out toy trains, running shoes, designer purses, house paint, cellular phones and more, a city "where everything is in the process of becoming something else."

"Most of my friends in Beijing had passed through the city but all they remembered — with a shudder — were the endless factories and the prostitutes. I had stumbled on this secret world, one that I shared with seven million, or eight million, or maybe ten million other people. Living in Dongguan was like arriving in it for the first time, hurtling down the highway at seventy miles an hour, the scenery changing too fast to keep track of it. Dongguan was a place without memory."

These journeys have shifted migrants away from generations of tradition: studying the "correct" subjects before entering the work force, marrying someone from the village, obeying one's parents, all suddenly are negotiable. It's mobile phones rather than village elders that contain business contacts, friends and potential mates. Now, height, weight and beauty translate into economic opportunity (or lack thereof) as much or more than education, class or connections.

Chang finds migrants simultaneously excited and stressed by these changes. Here's her account of a "White-Collar Class" designed for those who aspire to management.

"The language of self improvement suffused ordinary commercial life as well: Direct-sales companies, headhunters and matchmakers all made their sales pitches in the vocabulary of aspiration. The bookstores of Dongguan were wall-to-wall self improvement volumes. Some stores had no other sections ... self-help might be an American invention, but the Chinese had refined and renamed the genre to reflect their own narrower preoccupations: chenggong xue, success studies."

Occasionally, Chang's storytelling suffers due to an overwhelming number of voices. But that confusion seems also an apt homage to the dizzying lifestyle changes migrants experience. She mingles her own family's history of achievement, risk and sacrifice to great effect, providing a solid overview of Chinese history, context and insight as she travels the country to weave together the wisps of memory gleaned from a lifetime of family stories.

"Almost a hundred years ago, my grandfather had been a migrant too. He had left his village, changed his name, and tried to remake himself for the modern age. In his youth, China was emerging from a long, self-imposed isolation to rejoin the world — and so it is again today. My grandfather left home for good when he was sixteen years old — although he probably did not know it then, just as today's migrants might not know it now. Chuqu, to go out: This is how the story of my family also begins."